Mechanical Behavior of Shale Rock under Uniaxial Cyclic Loading and Unloading Condition

Table 1

Parameters of the viscoelastic-plastic creep model.

Stress level (MPa)	E1 (MPa)	E2 (MPa)	η2 (MPa·min)	η0 (MPa·min)	α	β	R^2
27.16	13667.22	120846.50	1123865.91	3356791.52	0.02	2.58	0.988
35.16	12528.82	457903.91	2265214.34	219.08	−7.65	0.08	0.997
43.16	11899.18	63875.70	1.45E + 16	51177.93	−2.65	0.19	0.959
51.16	11520.01	432090.97	110414.84	999684.64	−8.34E − 06	7.80	0.990